How sinking violence separates turrets from a wreck

How can magazine damage and sinking make Hood's turrets come off their barbettes?

Explosion pressure and violent hull movement can unseat the turrets before impact with the seabed.

A turret's immense weight does not mean it is permanently fastened to the hull against every direction of force. Magazine pressure can lift or displace the mounting when the surrounding structure fails. The hull may also twist, roll and break as it sinks, leaving a turret no longer seated on its barbette. Descent is usually a violent crash rather than a smooth glide, so the wreck can be rearranged before it reaches the seabed.